Botanical chronicles: Part 2- All about families

As an amateur gardener, my goal extends beyond mere cultivation. As a dedicated plant collector—peonies being a particular favorite among many—I find immense fascination in understanding the botanical families that define and connect my plants. In this blog post, I will introduce the intricate relationships that bind ornamental and edible plants within botanical families, offering valuable insights to enhance your gardening expertise.

The importance of botanical families

Botanical families serve as the fundamental building blocks of plant taxonomy, providing a systematic framework to organize the vast diversity within the plant kingdom. For gardeners, this classification system is a valuable tool that extends beyond the mere aesthetic appeal of a plant. It offers insights into a plant’s nomenclature, its various components, growth habits, preferred soil conditions, and even its susceptibility to pests and diseases.

In a prior blog post, I emphasized the significance of genus and species names in plant identification. Understanding botanical families now introduces another layer of knowledge to botanical taxonomy.

The arrangement of plants into families by botanists illuminates the relationships between different genera and species. To appreciate this concept fully, let’s revisit the origins of plant classification

The pioneers of plant classification

The task of organizing plants into families began centuries ago, driven by a desire to bring order to the vast array of plant species. Two influential figures stand out in the history of botanical classification:

  1. Carl Linnaeus (1707–1778):
    • Linnaeus, a Swedish botanist, is often hailed as the father of modern taxonomy. In the 18th century, he introduced the binomial nomenclature system, assigning each plant a unique two-part name based on genus and species. While Linnaeus focused primarily on sexual characteristics for classification, his work laid the foundation for organizing plants into a hierarchical structure.
  2. Augustin Pyramus de Candolle (1778–1841):
    • Building on Linnaeus’s work, de Candolle, a Swiss botanist, emphasized a more comprehensive approach to plant classification. He considered not only reproductive structures but also a range of morphological and anatomical features. De Candolle’s efforts contributed significantly to the understanding of plant relationships.

Systems of classification

Over time, different systems of classification have emerged, each offering unique perspectives on plant relationships. Two noteworthy systems are the artificial system and the natural system:

  1. Artificial system:
    • The artificial system, primarily developed by Linnaeus, relies on easily observable characteristics such as the number and arrangement of floral organs. While this system is straightforward and practical for identification purposes, it doesn’t reflect evolutionary relationships among plants.
  2. Natural system:
    • The natural system, championed by botanists like de Candolle and later refined by others, seeks to classify plants based on their evolutionary relationships. This system considers a broader range of characteristics, including morphological, anatomical, and genetic traits. The goal is to group plants that share a common ancestry, providing a more nuanced understanding of their connections.

Modern advances in classification

In the modern era, advancements in molecular biology have revolutionized plant classification. DNA sequencing has become a powerful tool for determining genetic relationships among plants. The advent of phylogenetics, the study of evolutionary relationships, has led to the development of the phylogenetic system, which uses genetic data to classify plants based on their evolutionary history.

Naming families

In botanical nomenclature, family names in Latin typically end with the suffix “-eae,” reflecting a shared convention in classifying plant groups. Certain botanical families bear the name of a popular genus within them, a practice that not only reflects the significance of that genus within the family but also aids gardeners and botanists in identifying and understanding the characteristics of plants within those families. Translating a family name in English involves using the accepted English equivalent or common name for that particular botanical family. The best example of both English common name and scientific name is probably the Rose Family, Rosaceae, but not all families take that simple approach!

General criteria to define families

Botanists consider a range of characteristics to include a plant in a family, including:

  1. Morphology: The physical structure and form of plants, such as the arrangement of leaves, types of flowers, and overall plant architecture, play a crucial role in family classification.
  2. Reproductive features: Botanists examine the reproductive structures of plants, including flowers, fruits, and seeds. Shared reproductive features often indicate a closer evolutionary relationship.
  3. Genetic analysis: As said before, with the advancements in molecular biology, genetic analysis has become a powerful tool for classifying plants. DNA sequencing allows botanists to compare the genetic makeup of different species and identify common ancestry.
  4. Ecological adaptations: Plants within the same family often share ecological preferences. Understanding these adaptations can guide gardeners in providing the right growing conditions for their plants.

Identifying flowers through botanical families

As a botanist, when faced with an unfamiliar plant, my initial focus is on its flowers whenever possible, or occasionally on the fruit. This approach provides crucial clues to discern the family to which the unknown plant may belong. Consequently, one of the practical advantages of comprehending botanical families is the enhanced ability of gardeners to identify plants through their distinctive flowers or fruits. Conversely, having knowledge of a plant’s family affiliation offers valuable insights into its characteristics. For example:

  1. Leaf arrangement:
    • Many plants within the same family exhibit similar leaf arrangements. Whether they are alternate, opposite, or whorled can be a key identifier.
  2. Flower structure:
    • The arrangement and structure of flowers often follow a pattern within a botanical family. Whether they are solitary or in clusters, the number of petals, and the presence of specific features like bracts can aid in identification.
  3. Fruit characteristics:
    • The type of fruit a plant produces is often a distinctive feature of its family. Whether it’s a capsule, berry, or achene, understanding these characteristics narrows down the possibilities.
  4. Growing habit:
    • The growth habit of a plant, such as whether it’s a shrub, tree, herb, or vine, is often consistent within a botanical family.

7 prominent flowering plant families in my gardens and their significance

1. Rosaceae: The rose family

The Rosaceae family includes some of the most beloved garden plants, such as roses, strawberries, and crabapples. Understanding the common characteristics of this family, such as compound leaves and often showy flowers typically bearing five petals and numerous stamens, creating a visually appealing radial symmetry. Rosaceae flowers are often fragrant, enhancing their ornamental value. Many species in this family produce fleshy fruits, contributing to their economic importance and popularity in gardens. Overall, the Rosaceae family offers a diverse array of blooms, combining beauty with practical utility.

Crabapple flowers (Malus cv,)

2. Lamiaceae: The mint family

Known for aromatic leaves and square stems, the Lamiaceae family encompasses herbs like mint, basil, and rosemary. Their flowers are arranged in compact clusters, forming whorls or spikes along the stem. The flowers often have a tubular shape with a two-lipped structure, showcasing bilateral symmetry. They attract pollinators with their nectar and provide a visually appealing addition to gardens and landscapes. By recognizing these shared traits, you can create aromatic herb gardens that not only provide culinary delights but also is nature friendly while detering pests through natural means.

Agastache ‘Astello Indigo’

3. Fabaceae: The legume family

Legumes, like peas and beans, belong to the Fabaceae family. Typically, the flowers are bilaterally symmetrical and composed of a standard, wings, and a keel, forming a structure known as a papilionaceous or butterfly-like flower. This unique arrangement is a key feature of many legumes, including peas, beans, and clovers. The family is known for its economic importance, providing essential crops, and the flowers often develop into pods containing seeds. This family is not only valued for its culinary contributions but also for its ability to fix nitrogen in the soil, enriching it for neighboring plants. Incorporating legumes into your garden can contribute to sustainable and nutrient-rich soil. The legume family also includes some trees like the catalpa and some ornamental perennials like the lupine.

Ornamental lupine (Lupinus polyphyllus cv.)

4. Asteraceae: The sunflower family

Comprising sunflowers, daisies, dahlias, zinnias and asters, the Asteraceae family is the largest family of flowering plants. Exhibiting distinctive features, their blooms are composed of many small individual flowers clustered together in a composite head, creating the appearance of a single, large flower. Thus why they used to be called before Compositae. This inflorescence structure is surrounded by bracts, which may be colorful and petal-like, contributing to the overall attractiveness of the flower head. Understanding their preferences for full sun and well-drained soil can guide you in creating vibrant, sun-kissed corners in your garden.

Daisy Polaris

‘Polaris’ daisy (Leucanthemum × superbum ‘Polaris’)

5. Peoniaceae: The peony family

The Peoniaceae family includes the renowned peony plants (Paeonia) known for their large, fragrant blooms in various colors. These, originally characterized by simple blooms with five petals, have evolved to showcase large, showy forms and ornamental features. As a result, many peonies now boast flowers with numerous petals arranged in a lush, full form, creating a visually striking appearance. These ornamental perennials thrive in well-drained soil and prefer ample sunlight. Cultivating peonies can add elegance and charm to your garden, creating vibrant and enchanting corners.

Paeonia lactiflora Primevère

Primevère peony (Paeonia lactiflora ‘Primevère’)

6. Ericaceae: The heath family

The Ericaceae family encompasses diverse plants like rhododendrons, heather and blueberries. Many members of this family have bell or urn-shaped structure, with a tubular or flaring corolla adapted for pollination by insects. The petals and sepals are often fused, forming a tubular or bowl-shaped structure. The number of petals can vary, but they typically come in multiples of five. The flowers are arranged in clusters or racemes, adding to their visual appeal. With unique characteristics and preferences, these acid-loving plants thrive in well-drained, acidic soil and partial shade.

Azalea ‘Tri Lights’ (Rhododendron ‘Tri Lights’)

7. Liliaceae: The lily family

The Liliaceae family is a diverse group of flowering plants that includes iconic blooms like lilies, tulips and daylilies. Known for their exquisite flowers and varying forms, these plants add grace and elegance to gardens. Lilies and their relatives typically prefer well-drained soil, ample sunlight, and moderate watering. The flowers within this family are often characterized by their six petal-like tepals, giving them a distinctive and visually appealing symmetry. Additionally, many members of the Liliaceae family propagate through underground bulbs, contributing to their popularity in horticulture and making them a favored choice for gardeners seeking perennial beauty.

Lilium oriental 'Corvara'

Oriental lily ‘Corvara’ (Lilium ‘Corvara’)

7. Iridaceae: The iris family

The Iridaceae family, often known as the iris family, encompasses a diverse range of flowering plants, each distinguished by their unique and captivating blooms. Typically, iris flowers are distinguished by their unique structure, featuring three upright petals called standards, three outer drooping petals known as falls, and a central style branch often adorned with crests or markings. Members of the Iridaceae family typically thrive in well-drained soil, and they exhibit preferences for varying sunlight conditions depending on the species. Notably, many plants in this family grow from underground corms or rhizomes, contributing to their adaptability and resilience in garden settings.

Dwarf iris ‘Blue Denim’ (Iris pumila ‘Blue Denim’)


As an amateur gardener, my journey involves more than just nurturing plants; it’s about understanding the interconnected web of botanical families and scientific nomenclature that make each plant unique. By delving into the relationships between plants, anyone can enrich their knowledge and gardening experience while fostering a garden that flourishes in both beauty and vitality. So, the next time you stroll through your garden, take a moment to appreciate the kinship that exists among your plants – a testament to the intricate dance of nature that you, as a fellow gardener, play a vital role in orchestrating.

Further reading

One reputable website with scientific authority on botanical families is the International Association for Plant Taxonomy (IAPT). This organization is dedicated to the advancement of plant taxonomy and provides valuable resources and information on plant classification, including details about various botanical families.

The WFO Plant List or World Flora Online provides a global overview of the diversity of plant species. While browsing the plant list or searching a scientific plant name in the comprehensive database, you obtain its complete current classification while providing the accepted scientific names for all taxa (families, genera, species, etc.).

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